Spirit-level



(No Model. D I

E. F. ST. JOHN.

SPIRIT LEVEL.

No. 375,222. Patented Dec. 20, 1887.

INVENTOR I Z flwaadzza. J g ;a 24% YBY M w ATTOR N. PETERS. Pllulo-Lilhngnphar, Walhlngtom D C.

UNITED STATES PATENT OFFICE.

ENOS F. ST. JOHN, OF HIGHLAND STATION, MICHIGAN.

SPl RlT-LEVEL,

SPECIFICATION forming part of Letters Patent No. 375,222, dated December 20, 1887.

Application filed March 12, 1887. Serial No. 230,643. (No model.)

To all whom it may concern.-

Be it known that I, ENos F. ST. JOHN, of Highland Station, in the county of Oakland and State of Michigan, have invented a new and Improved Spirit-Level, of which the following isafnll, clear, and exact description.

This invention relates to a novel form of spirit-level, wherein the parts are so. arranged that the instrument may not only be used for obtaining level or perpendicular lines, but may also be used for obtaining any desired intermediate angle; and to this end the invention consists of a circular tube that is partially filled with spirit or other proper liquid, and mounted in connection with a semicircular graduated plate, as will be hereinafter more fully described, and specifically pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar figures of reference indicate corresponding parts in all the views.

Figure l is a face view of my improved form of spirit-level. Fig. 2 is a rear view thereof,

and Fig. 3is a sectional plan view taken upon line 00 w of Fig. 2.

In constructing such a level as the one forming the subject-matter of this application, I take a block or strip, 10, in one face of which there is formed a flat semicircular rec'ess,within which there is mounted a tube, 11, that is partially filled with spirit or other proper liquid, an air-bubble being left within the tube, as indicated by dotted lines at 2 in Fig. 1. This tube llis held to place by a faoin gplate, 12,

a that is secured to the face of the block or strip 10 by screws 3. Above the tube 11, I arrange a graduated semicircular plate, 13, the degrees being marked from the vertical center of the plate downward to the -degree mark, and from the lower ends of the plate upward to the 4.5-degree mark; and if this plate is made to extend below the axis of the circle to which the plate and the tube conform the graduations might be extended downward from the zero-mark at each end of the plate, this arrangement being shown in the drawings.

An inspection of Fig. 1 will show that the tube is visible above the plate 12, and it will be understood that when the block or strip 10 is placed upon a level the center of the bubble shown at 2 will be in line with the upper zero-mark of the plate 13, and that by tilting the block or strip 10 to either side until the center of the bubble is in line with the desired angle any angle may be obtained.

In order that the tube 11 may be seen from the rear of the block or strip 10, I form said strip with apertures 14 and 15, said apertures being so located that the bubble may be seen from the rear side when the block or strip 10 is held in the horizontal or perpendicular position.

Having thus fully described my invent-ion,I claim as new and desire to secure by Letters Patent- 1 1. As an improved article of manufacture, a spirit-level consisting of a stock having sightopenings, a semicircular spirit-tube fitted inone face of the stock, and a graduated semicircular plate above the tube, as specified.

2. In a spirit level, the combination, with a stock, 10, having a semicircular recess in one face and provided with the sight-openings 14 and 15, of the semicircular spirit-tube arranged in the said recess, the securing-plate 12, and the semicircular graduated plate 13, secured to the stock above the spirit-tube, substantially as herein shown and described.

ENOS F. ST. JOHN.

Witnesses: V

FREDERICK HARRIS, KITTY HARRIS. 

